Annular cutter



0. w. BAKER ANNULAR CUTTER July 26, 1949.

Filed June 15,1948

Cora/in WBa/yer' Patented Juiy 26, 1949 AN NULAR CUTTER .Corwin .W. Baker, Beverly, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application June 15, 1948, Serial No. 33,205

Claims. 1

The purpose of this invention is to provideimprovements in tapered annular cutters such, for example, as those commonly used in machines of the .type illustrated in United States Letters Patent No. 1,226,872, granted May 22, 1917, on application of AndrewEppler. Such machines are used to trim the inseams of welt shoes, and in the process of doing so the cutters thereof encounter many lasting staples or tacks and soon become dulled thereby, especially if they are made of. the kind of steel that may be bent to. transform a thin flat blank into a conical annulus, asrepresented in the patent above mentioned. After a cutteryblank of'that type has been bent to, the required form, its meeting edges must be welded to each other, the welded seam or. joint dressed to remove surplus metal, the interior of the annulus machined with a milling cutter to form flutes, and the fluted annulus hardened and tempered. Some of 'the technical :5,

difiiculties incidental to making cutters in that manner are set forth in United States Letters Patent No. 1,720,769, granted July 16, 1929, on application of R. O. Stephenson.

To avoid those difficulties and, at the same time, to facilitate making tapered annular cutters of more durable steel without bending, straining, or welding the latter, the present invention provides a novel construction whereby an annular cutting edge comprising a series of scallops may be obtained with a plurality of individual fiat cutting bits or blades so shaped and assembled as to form a hollow truncate pyramid. Although the cross-section of such a cutter is essentially polygonal both inside and outside, a truly annular cutting edge may be formed at the larger and of the cutter by rinding a narrow concentric circular band on the outer faces of the blades.

Another novel feature of the invention is embodied in a combination of cooperative clamping members constituting a stock by which all the flat bits or blades of an annular cutter are maintained in pyramidal relation. One of these clamping members is provided with exterior facets forming a truncate pyramid, each facet providing a seat for the inner face of the shank of one blade. The other one of the clamping members is provided with an interior truncate conical surface having an angle of taper corresponding to that of the pyramidal clamping member.

Referring to the drawings, Fig. 1 is a front elevation, partly broken away, of a cutter assemblage embodying the invention; Fig. 2 is an end elevation thereof, except the portion in section in the plane of line II-II in Fig. 1; I

Fig. 3 is an end elevation of a segment of the outer blade-clamping member;

Fig. 4 is an end elevation of a segment of the inner blade-clamping member; and

Fig. 5 is a perspective View of one of the blades.

A cutter assemblage embodying the invention comprises a plurality of uniform individual flat blades l0, preferably made of high-speed steel, and a stock by which they are carried and maintained in the form of a hollow truncate pyramid. The stock is preferably designed to facilitate attaching and detaching the blades Hi. It

comprise-s a hub II, a nut l2 engaging a thread on the hub, an inner clamping member l3 and an outer clamping member M. .The hub is provided with an internal circular bearing surface I5 adapted to establish an aXis of rotation indicated by. line X-X in Fig. 1. The hub is adaptedto be mounted on a dead spindle I6 in an inseam-trimming machine in the manner illustrated in Fig, 9 of the aforesaid Eppler Patent No. 1,226,872, and is provided with gear teeth I! by which it may be rotated.

To provide necessary clearances in a machine of the type under; consideration, the cutter assemblage is tapered as illustrated in Fig. 1, its larger end being defined by an endless series of outcurved segmental cutting edges I8 provided one by each blade Hi. All portions of the composite cutting edge thus formed are equidistant from the axis of rotation, although they do not lie all in one plane.

Each blade has a narrow shank end I 9, a wider cutting end, and two straight side edges 20. 20 converging from the cutting end to the shank end.

The inner clampin member I 3 is provided with a series of blade-engaging facets 2! that give it the form of a truncate pyramid, and. they are surrounded by an interior frusto-conical bladeengaging surface 22 of the outer clamping member I l. The proportions, angles and dimensions of the clamping members and of the blades are coordinated to maintain the latter in the form of a hollow truncate pyramid and to maintain their converging edges 20 in abutting relation (Fig. 2). Consequently, when the assemblage is intact and the clamping members are set up tightly against the blades, each blade is braced against sidewise displacement and skewing by the two blades that flank it.

The blades and one of the clamping members are preferably provided with interlocking formations of which are equidistantafromsaid axis."

' 3 y tions adapted to prevent the blades from creeping out of their allotted places. For this purpose the shank portion of each blade may be provided with a small round hole 23 and one of the clamping members may be provided with a series of anchoring studs 24 adapted to project into the holes.

The drawings represent the studs as fastened to,

the member-1'3 bylbeinggpressed'into tightlyfitting bores therein. a

The blades may be assembled and clamped in the stock before their cutting ends are provided with cutting edges. To form the cuttingfififiges the'assemblage will be rotated about its axis" while an abrading wheel is operated toigeifieratezasconi vex exterior bevel 25 that intersects the inter'ior 1 The surface' generated 1 by the abradingcwheel is prefil fi il :sfiiylindrical,

faces of all the blades.

and the bevel thereby formed is due to the Icon,

conical surface, an inner clamping member having a series of exterior facets forming the sides f of a truncate pyramid and'surrou'nded by said frusto-conical surface, arseries of uniform individual flat blades seated respectively on said facets and having'straight converging edges abutting one another, andmeans by which said clamping members" are maiiitainedigwinst saidbl afles with clampingpres'sure, said bla 'des projecting from said clamping. members and forming a hollow truncate pyramid having a circular exterior bevel l- ,zat its larger end intersecting the interior flat faces of the blades, said bevel and said interior faces vergence of the blades. Furthermore, since 'the V interior faces of the blades are fiat, the result oflbevelingxthe onterrfaces.asispecifiedziseanrannw lar cutting edge having outcurved scallops. g I: iizliaving thus described ;my invention, :-what I claim as new and;zdesireutoaseeure:-by:Letters Baitent oftdzhesllnited Statessis:

1. An annular.xcuttemcomprisingeazplurality.of

* cutting edge having outr ilrv d' scellpps. a r V ?4.*A1j. armular ciitter comprising a stock memgber -haying a series of exterior facets forming a truncate pyramid, a series of individual fiat blades eah having a shank end, a wider cutting end and two straight edges converging from the a cuttingsendgtoztheslinnleienmjithmshanlclpontiohs individuafl-z-flat :blades leach havingia wide cutting end, za-:-narrow sharn'k end andttwo .straightlcon-j vergingazside lzedges faznd v-means lconstituting a stock: tomvhieh: thee-narrow ends .of: .said blades anerzfastenedcsidersby :sidein 1a. seriesjin .sthe lform ofeazholl'ow. itruncateipyramid inwhich saidaconverging gedgeszaibnt qnesanother, themride I1d0feach. 'laladezhavingl an exterior convex bevelinter secting thegl'mterior fiat tace thereof and iorminga *curved remitting. edge.

azzlg Am cutterrcomprising astocli having acimularebearinglsurface adapted toesta'blish-an axis of rotation, and aJpIuraIity, :of individuals-flat blades :fastened 1 ingedge-itmedge relation to .isaid stock endless: seriesn'forming astruncate pyramid i 00110811111110;: With' SBid .Laxis, usaidxiblades having-each aficrrttingxed'ge at one; end :andfiorming collectively, .anann'u'lar muttingedgelall por Egan i, annular icutter {comprising an i outer clamping emember -l having an =interiori=frusto czfisaidiblades'heingeseated :omsaid facetar'lrespec tively;;-nrrd isaidrrstrai'ghtie'dge ying oneea'gainst another, :said:stocle'sriremberaandathe shank mor tions off the: b latlesliehalvlirrg.iinterilocking idrma by. bladesc'are cla'mped anemamtainca r in i-thesform ot a hollew tnuncate pymmim one or s'a-"immemberszvhaving an inter-mmmsto omcn bladeeengaging surfiface fisurrounding the shank he other'=- having bladeengiazg-ing: facets "formi truncate p'yre mid-against-whicm Zth bar-11b portions (W ther bladesare clamped by:saidsfrusto conical surfaee.

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